<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html lang="en">
<head>
	<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
	<title>Document</title>
	<style type="text/css">
	.father{
		width: 400px;
		height: 400px;
		border: solid #FF6700;
		position: relative;
	}
	.box{
		width: 400px;
		height: 400px;
		border: solid green;
		position: absolute;
	}
	.box1{
		width: 200px;
		height: 200px;
		border: solid red;
		position: absolute;
	}
	.box2{
		width: 200px;
		height: 200px;
		border: solid blue;
		position: absolute;
	}
	.box3{
		width: 200px;
		height: 200px;
		border: solid yellow;
		position: absolute;
	}
	</style>
</head>
<body>
	<div class="father">
	<div class="box"></div>
	<div class="box1">1</div>
	<div class="box2">2</div>
	<div class="box3">3</div>
	</div>
</body>
</html>